Effect of cardiosphere-derived cells on segmental myocardial function after myocardial infarction: ALLSTAR randomised clinical trial

BACKGROUND

Most cell therapy trials failed to show an improvement in global left ventricular (LV) function measures after myocardial infarction (MI). Myocardial segments are heterogeneously impacted by MI. Global LV function indices are not able to detect the small treatment effects on segmental myocardial function which may have prognostic implications for cardiac events. We aimed to test the efficacy of allogeneic cardiosphere-derived cells (CDCs) for improving regional myocardial function and contractility.

METHODS

In this exploratory analysis of a randomised clinical trial, 142 patients with post-MI with LVEF <45% and 15% or greater LV scar size were randomised in 2:1 ratio to receive intracoronary infusion of allogenic CDCs or placebo, respectively. Change in segmental myocardial circumferential strain (Ecc) by MRI from baseline to 6 months was compared between CDCs and placebo groups.

RESULTS

In total, 124 patients completed the 6-month follow-up (mean (SD) age 54.3 (10.8) and 108 (87.1%) men). Segmental Ecc improvement was significantly greater in patients receiving CDC (-0.5% (4.0)) compared with placebo (0.2% (3.7), p=0.05). The greatest benefit for improvement in segmental Ecc was observed in segments containing scar tissue (change in segmental Ecc of -0.7% (3.5) in patients receiving CDC vs 0.04% (3.7) in the placebo group, p=0.04).

CONCLUSIONS

In patients with post-MI LV dysfunction, CDC administration resulted in improved segmental myocardial function. Our findings highlight the importance of segmental myocardial function indices as an endpoint in future clinical trials of patients with post-MI.

TRIAL REGISTRATION NUMBER

NCT01458405.

Analysis of recurrent events with an associated informative dropout time: Application of the joint frailty model

This paper considers the analysis of a repeat event outcome in clinical trials of chronic diseases in the context of dependent censoring (e.g. mortality). It has particular application in the context of recurrent heart failure hospitalisations in trials of heart failure. Semi‐parametric joint frailty models (JFMs) simultaneously analyse recurrent heart failure hospitalisations and time to cardiovascular death, estimating distinct hazard ratios whilst individual‐specific latent variables induce associations between the two processes. A simulation study was carried out to assess the suitability of the JFM versus marginal analyses of recurrent events and cardiovascular death using standard methods. Hazard ratios were consistently overestimated when marginal models were used, whilst the JFM produced good, well‐estimated results. An application to the Candesartan in Heart failure: Assessment of Reduction in Mortality and morbidity programme was considered. The JFM gave unbiased estimates of treatment effects in the presence of dependent censoring. We advocate the use of the JFM for future trials that consider recurrent events as the primary outcome. © 2016 The Authors. Statistics in Medicine Published by John Wiley & Sons Ltd.

The effect of HAART on salivary microbiota in the Women's Interagency HIV Study (WIHS)

OBJECTIVE

Study the prevalence of potentially pathogenic microorganisms in saliva of HIV-positive women in the Women's Interagency HIV Study.

STUDY DESIGN

157 HIV-positive and 31 HIV-negative women were studied. At baseline and every 6 months over 4 years, information was collected on socioeconomic and educational status, oral and systemic health, including HIV markers and antiretroviral therapy, and frequency of professional oral care utilization. Bacterial and yeast pathogenic isolates from stimulated whole saliva were tentatively identified using standard methodologies.

RESULTS

The prevalence of microorganisms in stimulated saliva of HIV-positive women was not significantly different from that of HIV-negative women. In HIV-positive women, highly active antiretroviral therapy (HAART) was independently and significantly associated with the presence of a variety of salivary bacterial species. HAART increased the risk for recovering Fusobacterium species (P < .001), enteric gram-negative rods (P < .05), Peptostreptococcus micros (P < .05), Campylobacter species (P < .0001), Eubacterium species (P < .001), and Tannerella forsythia (P < .01). In contrast, HAART led to decreased recovery rate of yeasts (Candida albicans and Candida dubliniensis) (P < .0001).

CONCLUSION

The present findings suggest that the institution of HAART promotes an increasingly pathogenic salivary microbiota, at least temporarily. Similar findings have been reported for various nonoral microbial ecosystems.

Exposure stratified case-cohort designs

A variant of the case-cohort design is proposed for the situation in which a correlate of the exposure (or prognostic factor) of interest is available for all cohort members, and exposure information is to be collected for a case-cohort sample. The cohort is stratified according to the correlate, and the subcohort is selected by stratified random sampling. A number of possible methods for the analysis of such exposure stratified case-cohort samples are presented, some of their statistical properties developed, and approximate relative efficiency and optimal allocation to the strata discussed. The methods are compared to each other, and to randomly sampled case-cohort studies, in a limited computer simulation study. We found that all of the proposed analysis methods performed well and were more efficient than a randomly sampled case-cohort study.

Relationship of isoniazid resistance to human immunodeficiency virus infection in patients with tuberculosis

To investigate the relationship between isoniazid resistance and HIV infection in patients with tuberculosis, we evaluated data in the Los Angeles County tuberculosis registry on 1,506 patients for whom drug susceptibility results were available. Among 235 HIV-infected patients, isoniazid resistance was less common than in 1,271 patients who were HIV-seronegative or who had not been tested for HIV, with an unadjusted odds ratio of 0.3. After adjustment for other factors that affect drug resistance (ethnicity, country of birth, prior diagnosis of tuberculosis, and cavitation), the frequency if isoniazid resistance remained lower than that in patients without HIV infection, with an odds ratio of 0.4 (95% confidence interval, 0.2 to 0.8; p = 0.02). We conclude that in Los Angeles, a setting where there is no ongoing outbreak of drug-resistant tuberculosis, isoniazid-resistant tuberculosis is not more common in HIV-infected patients.

Transmission of tuberculosis among the urban homeless

OBJECTIVE

To determine the relative frequencies of primary and reactivation tuberculosis in the urban homeless.

DESIGN

Prospective evaluation of homeless tuberculosis patients.

SETTING

Central Los Angeles, Calif.

PATIENTS

Thirty-four homeless patients with culture-proven tuberculosis.

INTERVENTIONS

IS6110-based restriction fragment length polymorphism (RFLP) analysis was performed on Mycobacterium tuberculosis isolates. If results were inconclusive, pTBN12-based RFLP analysis was performed.

MAIN OUTCOME MEASURE

Clustering of M tuberculosis isolates. A cluster consisted of two or more isolates with indistinguishable RFLP patterns.

RESULTS

Twenty-four of 34 homeless patients had clustered isolates in six clusters.

CONCLUSIONS

The minimum percentage of cases due to primary tuberculosis in the homeless was estimated to be 53%, compared with the traditional estimate of 10% in the general population. The results suggest that primary tuberculosis caused the majority of tuberculosis cases in this population of the urban homeless in central Los Angeles.

Los Angeles study of residential magnetic fields and childhood brain tumors

A measurement study of residential magnetic fields and brain tumors in children that was added onto an ongoing case-control interview study in Los Angeles County, California, include 298 children under age 20 years with a primary brain tumor diagnosed from 1984 to 1991 and 298 control children identified by random digit dialing. Magnetic fields were determined for all Los Angeles homes where these 596 children lived from conception to diagnosis (1,131 homes) by mapping and coding the wiring configurations outside the home and by taking a series of exterior spot and profile measurements. In addition, for a subset of subjects (35%; 211 homes) 24-hour measurements were taken in the child's room and one other room. Although measured fields are consistently highest in the highest of the five wire code categories, fields in homes in this category are much lower in Los Angeles than in Denver, where the code originated. Brain tumor risk appears not to relate to measured fields inside (p for trend for child's room = 0.98) or outside (p for trend for front wall = 0.82) the home. An apparent increase in risk among children living at diagnosis in homes with underground wiring appears to be an artifact introduced by using current controls for historical cases because this apparent excess risk disappeared in an analysis restricted to the later years of the study when cases and controls were accrued concurrently. Our study does not show an overall association of pediatric brain tumors with measured fields, with "very high" wiring configurations, or with any of several other potential sources of exposure, such as use of various electrical appliances, but the prevalence of high fields (> 2 mG) and very high fields (> 3 mG) in Los Angeles homes was too low to detect a moderate effect of the magnitude reported in other studies.

Temporal modifiers of the radon-smoking interaction

Data on lung cancer mortality in a cohort of 3,347 Colorado Plateau uranium miners was reanalyzed to investigate the role of time-related modifiers of the radon-smoking interaction. A nested case-control sample of the cohort was drawn, matching each of the 258 lung cancer deaths with 15 controls drawn at random from the subjects who were born in the same year and still alive at the time the case died. As reported earlier, the dose response was sublinear for both total radon and total smoking, and their joint effect was approximately multiplicative. We fitted linear multiplicative models to these data, transforming the radon and smoking variables to improve their fit, and then added variables testing various temporal modifying effects and interactions. The strongest modifiers of the main effects of each variable taken separately were latency and duration of exposure. The strongest modifier of the interaction effect was the timing of radon and smoking exposures: Exposure to radon followed by smoking produced a significantly more-than-multiplicative effect, whereas the reverse sequence produced a significantly less-than-multiplicative effect. These findings suggest that smoking may act as a promoter of radon-initiated cells.

Evaluation of colestipol/niacin therapy with computer-derived coronary end point measures. A comparison of different measures of treatment effect

BACKGROUND

The Cholesterol Lowering Atherosclerosis Study has demonstrated beneficial effect of colestipol/niacin on coronary atherosclerosis using a panel-determined global coronary change score. We now report treatment group comparisons using quantitative coronary angiographic (QCA) measures from all processable segments in 85 of 162 randomly selected baseline/2-year film pairs.

METHODS AND RESULTS

Treatment benefit was established for percent stenosis for either continuous or categorical analyses with regression established regardless of the per-patient scoring procedure. In addition, treatment benefit favoring regression was established in some cases for roughness and for percent involvement, a longitudinal estimate of the percent of coronary surface involved by raised lesions. Benefit on minimum diameter was directly related to whether the segment was proximal to a graft insertion and hemodynamically related to the bypass graft. QCA correlates of panel-determined progression were increases in percent stenosis and numbers of occluded lesions in native arteries and the number of progressing lesions in bypass grafts.

CONCLUSIONS

These results demonstrate that a variety of computer measures can be used as end points in coronary angiographic therapy trials, but change in percent stenosis correlates best with visual panel assessments and best reflects the treatment benefit; when treatment effect sizes are moderate to large, the required sample size of coronary angiographic trials can be reduced when QCA is used.

Evaluation of human panelists in assessing coronary atherosclerosis

The Cholesterol Lowering Atherosclerosis Study, a randomized, angiographic clinical trial, has demonstrated the beneficial effect of niacin/colestipol therapy on coronary and femoral atherosclerosis. The primary outcome was a panel-determined consensus score evaluating global coronary changes determined angiographically at 2 years. This article presents an evaluation of interreader agreement in independently assessing the status of native coronary arteries and overall coronary condition. Parameters include 1) identification of the presence of lesions and lesion changes; 2) estimation of lesion severity (percent stenosis) and amount of change in lesion severity; and 3) global assessment of change in coronary status. Readers independently agreed on 1) presence of lesions (82%) and change in lesions (51%); 2) percent stenosis +/- 10% (76%) and change in stenosis +/- 10% (81%); and 3) global assessment of change in coronary status within one step (96%). Results of these analyses may be useful in effectively designing angiographic trials that use a panel of human evaluators as well as computerized methods for angiographic interpretation.